// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/shell/browser/shell_download_manager_delegate.h"

#if defined(OS_WIN)
#include <commdlg.h>
#include <windows.h>
#endif

#include "base/bind.h"
#include "base/command_line.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "build/build_config.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/download_manager.h"
#include "content/public/browser/web_contents.h"
#include "content/shell/common/shell_switches.h"
#include "net/base/filename_util.h"

#if defined(OS_WIN)
#include "ui/aura/window.h"
#include "ui/aura/window_tree_host.h"
#endif

namespace content {

ShellDownloadManagerDelegate::ShellDownloadManagerDelegate()
    : download_manager_(NULL)
    , suppress_prompting_(false)
    , weak_ptr_factory_(this)
{
}

ShellDownloadManagerDelegate::~ShellDownloadManagerDelegate()
{
    if (download_manager_) {
        DCHECK_EQ(static_cast<DownloadManagerDelegate*>(this),
            download_manager_->GetDelegate());
        download_manager_->SetDelegate(NULL);
        download_manager_ = NULL;
    }
}

void ShellDownloadManagerDelegate::SetDownloadManager(
    DownloadManager* download_manager)
{
    download_manager_ = download_manager;
}

void ShellDownloadManagerDelegate::Shutdown()
{
    // Revoke any pending callbacks. download_manager_ et. al. are no longer safe
    // to access after this point.
    weak_ptr_factory_.InvalidateWeakPtrs();
    download_manager_ = NULL;
}

bool ShellDownloadManagerDelegate::DetermineDownloadTarget(
    DownloadItem* download,
    const DownloadTargetCallback& callback)
{
    DCHECK_CURRENTLY_ON(BrowserThread::UI);
    // This assignment needs to be here because even at the call to
    // SetDownloadManager, the system is not fully initialized.
    if (default_download_path_.empty()) {
        default_download_path_ = download_manager_->GetBrowserContext()->GetPath().Append(FILE_PATH_LITERAL("Downloads"));
    }

    if (!download->GetForcedFilePath().empty()) {
        callback.Run(download->GetForcedFilePath(),
            DownloadItem::TARGET_DISPOSITION_OVERWRITE,
            DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS,
            download->GetForcedFilePath());
        return true;
    }

    FilenameDeterminedCallback filename_determined_callback = base::Bind(&ShellDownloadManagerDelegate::OnDownloadPathGenerated,
        weak_ptr_factory_.GetWeakPtr(),
        download->GetId(),
        callback);

    BrowserThread::PostTask(
        BrowserThread::FILE,
        FROM_HERE,
        base::Bind(&ShellDownloadManagerDelegate::GenerateFilename,
            download->GetURL(),
            download->GetContentDisposition(),
            download->GetSuggestedFilename(),
            download->GetMimeType(),
            default_download_path_,
            filename_determined_callback));
    return true;
}

bool ShellDownloadManagerDelegate::ShouldOpenDownload(
    DownloadItem* item,
    const DownloadOpenDelayedCallback& callback)
{
    return true;
}

void ShellDownloadManagerDelegate::GetNextId(
    const DownloadIdCallback& callback)
{
    static uint32_t next_id = DownloadItem::kInvalidId + 1;
    callback.Run(next_id++);
}

// static
void ShellDownloadManagerDelegate::GenerateFilename(
    const GURL& url,
    const std::string& content_disposition,
    const std::string& suggested_filename,
    const std::string& mime_type,
    const base::FilePath& suggested_directory,
    const FilenameDeterminedCallback& callback)
{
    DCHECK_CURRENTLY_ON(BrowserThread::FILE);
    base::FilePath generated_name = net::GenerateFileName(url,
        content_disposition,
        std::string(),
        suggested_filename,
        mime_type,
        "download");

    if (!base::PathExists(suggested_directory))
        base::CreateDirectory(suggested_directory);

    base::FilePath suggested_path(suggested_directory.Append(generated_name));
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE, base::Bind(callback, suggested_path));
}

void ShellDownloadManagerDelegate::OnDownloadPathGenerated(
    uint32_t download_id,
    const DownloadTargetCallback& callback,
    const base::FilePath& suggested_path)
{
    DCHECK_CURRENTLY_ON(BrowserThread::UI);
    if (suppress_prompting_) {
        // Testing exit.
        callback.Run(suggested_path, DownloadItem::TARGET_DISPOSITION_OVERWRITE,
            DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS,
            suggested_path.AddExtension(FILE_PATH_LITERAL(".crdownload")));
        return;
    }

    ChooseDownloadPath(download_id, callback, suggested_path);
}

void ShellDownloadManagerDelegate::ChooseDownloadPath(
    uint32_t download_id,
    const DownloadTargetCallback& callback,
    const base::FilePath& suggested_path)
{
    DCHECK_CURRENTLY_ON(BrowserThread::UI);
    DownloadItem* item = download_manager_->GetDownload(download_id);
    if (!item || (item->GetState() != DownloadItem::IN_PROGRESS))
        return;

    base::FilePath result;
#if defined(OS_WIN)
    std::wstring file_part = base::FilePath(suggested_path).BaseName().value();
    wchar_t file_name[MAX_PATH];
    base::wcslcpy(file_name, file_part.c_str(), arraysize(file_name));
    OPENFILENAME save_as;
    ZeroMemory(&save_as, sizeof(save_as));
    save_as.lStructSize = sizeof(OPENFILENAME);
    save_as.hwndOwner = item->GetWebContents()->GetNativeView()->GetHost()->GetAcceleratedWidget();
    save_as.lpstrFile = file_name;
    save_as.nMaxFile = arraysize(file_name);

    std::wstring directory;
    if (!suggested_path.empty())
        directory = suggested_path.DirName().value();

    save_as.lpstrInitialDir = directory.c_str();
    save_as.Flags = OFN_OVERWRITEPROMPT | OFN_EXPLORER | OFN_ENABLESIZING | OFN_NOCHANGEDIR | OFN_PATHMUSTEXIST;

    if (GetSaveFileName(&save_as))
        result = base::FilePath(std::wstring(save_as.lpstrFile));
#else
    NOTIMPLEMENTED();
#endif

    callback.Run(result, DownloadItem::TARGET_DISPOSITION_PROMPT,
        DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS, result);
}

void ShellDownloadManagerDelegate::SetDownloadBehaviorForTesting(
    const base::FilePath& default_download_path)
{
    default_download_path_ = default_download_path;
    suppress_prompting_ = true;
}

} // namespace content
